OLED devices offer an advantage over traditional inorganic LEDs that include color quality, diffuse light generation, and the potential for mechanical flexibility. However, current OLED device designs are not suitable replacements for inorganic LEDs in several applications, typically because of (1) lower electrical efficiency at the same light brightness level, and (2) encapsulation-related lifetime degradation.
A number of solutions have been obtained for the encapsulation-related lifetime degradation limitation, including glass-based encapsulation (including ultrathin and flexible glass substrates) as a means to increase lifetime while still enabling mechanical flexibility. However, electrical efficiency continues to be a challenge. Typically efficiency is measured as a function of the light that is emitted from the device and the efficiency of light output. Substrate structures having light extraction improvement of greater than about 2× (i.e., 2 times the external quantum efficiency of the referenced OLED device), are difficult to obtain in commercially viable structures.
The present disclosure addresses OLED efficiency by describing OLED structures with improved efficiency, wherein the OLED structures comprise patterned OLEDs with modified and patterned transparent conductors.